> The procedure is encapsulate the original VFP EXE in a packed file which is
> decompressed on memory prior to launch it.

Won't it be difficult to prevent malicious users from getting their hands on the decompressed - and thus unprotected - app?

You'd have to lock the user into the app so that they cannot switch to the start menu, the command prompt, or some running file manager (or any other app, for that matter); the app must not have Explorer-style file dialogs (since you can use those to copy files around), and all outgoing networks shares on the machine must be disabled so that people cannot do their copying over the network (good luck trying to keep users with admin privs away from the shares). And the Vulcan nerve pinch (CTRL-ALT-DEL) must be disabled as well (or hooked), naturally.

Another vulnerability is the compression/decompression code unless you have written it yourself and keep the source code locked up ... If you are using a publicly available algorithm or library then others can decompress the protected app directly.

> I'm continue working on it. Hold the line.

Would it not be more beneficial to think about the problem in terms of protocol and general principles first? Even a safe door with the most sophisticated locks offers no protection if people can simply walk around it or if the combination is etched into the metal beside the knob in large, friendly letters.

Hasta luego ...